1. Field of the Invention
This invention relates to a manufacturing method and a manufacturing apparatus of friction plate for clutch.
2. Related Art
A friction plate for clutch is used, in a clutch of a vehicle etc., to brake a rotating member such as rotor. It is comprised of a ring-shaped core plate and a plurality of friction material segments adhered to a surface of the core plate circumferentially. Japanese Patent Publication No. 4-6891 and Japanese Patent Laid-open No. 10-318309 have disclosed examples for manufacturing method and the manufacturing apparatus of friction plate for clutch. The manufacturing methods of the friction plate for clutch disclosed in these prior arts comprise a punching step for punching the friction material tape by a punching unit to form one piece of friction material segment, and a adhering step for adhering the punched friction material segment to an adhering surface of a core plate coated by an adhesive agent.
In detail, a band-shaped friction material is supplied above the core plate radially inwardly or tangentially to be punched into the friction material segment of a predetermined shape by the punching unit including a die and a punch. Then, the punched friction material segment is adhered to the adhering surface of the core plate by the punch just below the punching position. After adhering of the friction material segment to the core plate, the band-shaped friction material is supplied by the predetermined length and the core plate is rotated by the predetermined angle synchronous therewith, to perform forming and adhering of the next friction material segment. With repeating the punching step and the adhering step alternately by the times equivalent to the number of the friction material segments, all of the friction material segments have been adhered to the core plate circumferentially.
The manufacturing apparatus of friction plate for clutch is comprised of a supporting table supporting the core plate and intermittently rotating in every adhering of the friction material segment to the core plate, a supplying member for intermittently supplying the band-shape friction material over the supporting table by a predetermined length corresponding to length of the friction material segment, and a pressing member (punching unit) for punching the band-shaped friction material and for adhering the punched friction material segment to the core plate.
However, the above-mentioned manufacturing method and the manufacturing apparatus of Japanese Patent Publication No. 4-68491 and Japanese Patent Laid-open No. 10-318309, punching the band-shaped friction material and adhering the punched friction material segment to the core plate by the pressing member alternately by times equivalent to the number of the friction material segments, has been suffering from the following disadvantages.
A first disadvantage results from a characteristic change of the adhesive agent coated onto the core plate. Due to repeating punching step and the adhering step performed for each friction material segment, long time period is required from adhering of the first friction material segment to adhering of the last friction material segment. Therefore, characteristic of the adhesive agent having been coated on the core plate prior to punching of the band-shaped friction material changes between a start and an end of the friction material segment adhering to the core plate. Thus, adhering condition delicately differ for each of the friction material segments.
As a result, when all of the friction material segments are adhered to the core plate, particular friction material segment(s) may shift radially and/or circumferentially from a desired position on the adhering surface. Thus, positioning accuracy of the friction material segment may be deteriorated, which changes a relative position between the particular friction material segment and the friction material segment adjacent thereto. Thus, orientation and width of a radial groove formed between opposing sides of the adjacent friction material segments may change.
A second disadvantage results from wear of the punching unit. The die and the punch included in the punching unit forms one friction material segment by one operation thereof. So, for forming the plurality of friction material segments by the band-shaped friction material, the same die and punch are used by the plural times equivalent to the number of friction material segments. In addition, the same blade portion of the die and that of the punch are repeatedly abutted to the band-shaped friction material in every punching to be worn. Thus, the punching unit decreases punching ability thereof in short time period and requires to be changed.
As mentioned above, in the conventional manufacturing method and the manufacturing apparatus of friction plate for clutch, there has been room for improvement in the insufficient positioning accuracy of the friction material segment on the core plate. It results from uneven adhering condition of the plural friction material segments due to longer adhering time period. Also, there has been room for improvement in earlier wear of the blade portion of the punching unit and earlier exchange of the punching unit. It results from the same blade portion of the punching unit abutting to the band-shaped friction material repeatedly by times equivalent to the number of the friction material segments to be worn.
The present invention has been achieved in view of the above circumstances and intends to provide the manufacturing method and the manufacturing apparatus of friction plate for clutch which can overcome the above disadvantages of the conventional art. That is, the manufacturing method and the manufacturing apparatus of the present invention can adhere the plural friction material segments to the core plate in shorter time period than that in the conventional art. Thus, shifting of the friction material segment(s) in the circumferential and/or radial direction of the core plate due to uneven adhering condition can be prevented.
Also, the present invention intends to, in connection with the above-mentioned adhering manner of the friction material segments to the core plate, provide the manufacturing method and the manufacturing apparatus which can extend the durability life of the punching unit.
Inventors of the present invention pay attention to the fact that above-mentioned disadvantage results from punching the band-shaped friction material and adhering the friction material segments being repeated for each friction material segment, that is, the adhering step being carried out by the times equivalent to the number of the friction material segments. They hit on such disadvantages may be overcome by decreasing the number of time for adhering the friction material segment to the core plate.
A method for manufacturing a friction plate for clutch, comprising steps of a step for containing plural friction material segments on a one surface of a holding body circumferentially; and a step for making the one surface of said holding body and an adhering surface of a core plate coated with an adhesive agent come near to each other, and for adhering the friction material segments held by said holding body to the adhering surface of said core plate by urge.
The manufacturing method of the present invention can adhere in the adhering step the plural friction material segment held on one surface thereof in the containing step to the adhering surface of the core plate simultaneously or in very short time period. Thus, the time period required for adhering the plural friction material segments to the core plate has been greatly reduced compared with that in the conventional manufacturing method, so that all of the friction material segments are adhered to the core plate in the same adhering condition. As a result, the radial or circumferential shifting of the particular friction material segment can be prevented.
Also, the containing step, not including any adhering step between containing of the preceding friction material segment and the succeeding friction material segment, can contain the plural friction material segments into the holding body continuously. As a result, a punching unit of type punching the band-shaped friction material to form the friction material segment continuously at different punching blade parts can be adopted. Such punching unit can decrease the using frequency of the punching blade greatly to extend the durability life thereof.
Further, fiber fabrics formed around the friction material segment in punching the friction material tape by the first urging member extend opposite to pressing-in direction of the friction material segment into the holding body. However, the friction material segment is pushed out from the holding body opposite to the push-in direction in adhering to the core plate. So, the fiber fabrics nipped by the core plate and the friction material segment can not be observed, which improve appearance of the friction plate for clutch.
On the other hand, an apparatus for manufacturing a friction plate for clutch, comprising a holding body having a one surface for containing plural friction material segments circumferentially; a first urging member for urging the friction material segments to contain them in said holding body; a supporting member for supporting a core plate having an adhering surface coated by an adhesive agent; and a second urging member for urging the friction material segments held in said holding body to said core plate, at position where the one surface and the adhering surface come near to each other.
The manufacturing apparatus of the present invention can adhere the plural friction material segments held on one surface of the holding body simultaneously or in very short time period by urging with the second urging member.
In addition, the second urging member does not adhere any friction material segment between containing of the preceding friction material segment and the succeeding friction material segment by the first urging member. For this reason, the holding body and the first urging member can contain the friction material segments on one surface continuously by cooperation therebetweeen. As a result, a segment preparing member (punching unit) of type punching band-shaped the friction material to form the friction material segment continuously at different punching blade parts can be adopted. Such segment preparing member can decrease the using frequency of the punching blade greatly to extend the durability life thereof.
Embodying Mode of the Manufacturing Method of Friction Plate for Clutch
As mentioned above, the manufacturing method is comprised of the containing step and the adhering step.
The friction material segments are prepared in advance in a segment preparing step for punching or cutting a band-shaped friction material to form the friction material segment. The segment preparing step can punch the plural friction material segment continuously or intermittently. Also, the segment preparing step can be carried out for the band-shaped friction material obtained by compressing a band-shaped friction blank material with heating it. The band-shaped friction blank material can have plural cavities spaced longitudinally thereof or a groove extending longitudinally thereof. The segment preparing step is carried out prior to the containing step to be explained next, but they can be carried out continuously in one step or can be independently carried out in different or separate steps. The segment preparing step and the adhering step to be explained later can be carried out in different step concurrently.
Next, the containing step will be explained. The containing step can contain the friction material segment(s) into the holding body in a vertical direction toward one surface, ie, in a vertical direction relative to a surface of the friction material segment. This is convenient when one surface is formed on end surface of the circular-plate-shaped holding body. The containing step can contain the friction material segment(s) into the holding body along (parallel to) one surface radially inwardly, that is, in parallel direction relative to the surface of the friction material segment. This is convenient when one surface is formed by a step or a recess formed along an outer peripheral edge the circular-plate-shaped holding body.
The friction material segments can be contained by urging. For the urging, mechanical means such as an urging member etc. or hydraulic means such as air cylinder or an oil cylinder can be used. For the mechanical means, rod-shaped urging member advancing and retracting vertical to one surface can be adopted, which can ensure containing of the friction material segment into the holding body. For the hydraulic means, the holding member can have, at area where the segment containing portion is formed, an absorbing portion for absorbing the friction material segment under the reduced pressure. Absorbing the friction material segment can make the above rod-shape urging member unnecessary.
The containing step can contain, after having contained at least one friction material segments, the friction material segment(s) sequentially in the circumferential direction of the holding body. In other words, the two or more friction material segments can be contained into the holding body one by one. In this case, the containing step can include a positioning sub step for positioning each of the contained friction material segments at each of supplying portions by rotating the holding body, after each of the friction material segments is contained into each of the supplying portions. Rotating the holding body in the containing step of the friction material segments allows to supply the friction material segments at one or few supplying position(s). Also, it positions the contained friction material segment(s) at the supplying position spaced circumferentially on one surface of the holding body.
In addition, the containing step can contain at least two friction material segments simultaneously. In this case, two or more friction material segments are supplied into the non-rotatable holding body at two or more positions on one surface spaced circumferentially. Such containing manner can shorten time period for containing the friction material segments into the holding body.
A plurality of segment supplying portions (holding portions) are preferably formed on one surface of the holding body circumferentially. The segment holding portions can be comprised plural holding portions spaced circumferentially, or can be comprised of one ring-shaped holding portion. Also, the segment holding portion can be comprised of plural spaced concaved portions or one concaved groove formed on the end surface of the circular-plate-shaped holding body (here, bottom surfaces of the concaved portions or a bottom surface of the concaved groove forms the one surface). Further, it can be comprised of plural circumferentially spaced recesses or steps or one ring-shaped recess or step formed on an outer peripheral edge (corner) of the circular-plate-shaped holding body (here, a bottom surface(s) of the recess(es) or step(s) forms (form) the one surface). Plural friction material segments are preferably held on the one surface so that opposing sides of the adjacent friction material segments become parallel in the radial direction of the holding body.
Next, the adhering step will be explained. There is no restriction of positional relation between a containing position to contain the friction material segments into the holding body and an adhering position to adhere the friction material segments to the core plate. Accordingly, they can be positioned on the same axis, or on the different (parallel, for example) axes. However, in view of members or element required for containing and adhering the friction material segment, they are preferably disposed on different axes. In this case, the holding body and/or the core plate need to be moved so that the one surface and the adhering surface come near to each other. For this purpose, only the holding body or only the core plate can be moved, or both of the holding body and the core plate can be moved. When the holding body moves to and from the fixed core plate, it can revolve about a revolving axis, or can move in a direction parallel or vertical to the one surface thereof.
The adhering direction of the friction material segment to the core plate and the containing direction of the friction material segment into the holding body can be selected in opposite directions on the same axis or parallel axes, or in crossing (vertical, for example) directions. The friction material segments held in the holding body can be adhered to the core plate by an urging member held in the holding body shiftably relative thereto. The urging member can be driven by a driving portion such as an air cylinder or an oil cylinder. Such urging member can adhere (push out) the friction material segments to the core plate more securely. Also, the friction material segments held in the holding body can be adhered to the core plate by the urge using an absorbing. Further, the adhering step can adhere all of the contained friction material segments simultaneously, which can greatly shorten the time period necessary for adhering the plural friction material segments to the core plate.
The embodying modes described in each of the containing step, the adhering step and the segment preparing step capable of selectively combining should be noted.
Embodying Mode of the Manufacturing Apparatus of Friction Plate for Clutch
As mentioned above, the manufacturing apparatus is comprised of the holding body, the first urging member, the supporting member, and the second urging member.
The friction material segment can be prepared by punching or cutting a band-shaped friction material. The band-shaped friction material formed by compressing a band-shaped friction blank material to a predetermined thickness can be used. The band-shaped friction material can have plural cavities spaced longitudinally, or one groove extending longitudinally.
The segment preparing member can be provided independent from the first urging member to be explained next, or a part thereof can be formed by the first urging member. In the former case, the segment preparing member can be comprised of a rotatable cutting roller having plural cutting blades on an outer peripheral surface thereof. It can form plural friction material segments simultaneously. The latter case will be explained in the column of the first urging member.
The holding member can have various shape, but is preferably circular plate or circular pillar, in view of plural friction material segments being held on the cone surface thereof circumferentially. The one surface of the holding body can be formed on an end surface of the circular holding body, or on an outer peripheral edge (corner) thereof. In the former case, a bottom surface(s) of a concaved portion(s) can form the one surface, while in the latter case a surface(s) defining the recess(s) or step(s) can form the one surface. The holding body is preferably provided with plural segment supplying portions (holding portions) on the one surface thereof. The segment holding portions can be comprised plural concaved portion spaced circumferentially, or one concaved groove extending circumferentially on the end surface of the holding body. Also, they can be comprised of plural circumferentially spaced recesses or steps, or one ring-shaped recess or step. The one surface can have, at areas into which the friction material segments are contained, an absorbing portion to absorb the friction material segments under the reduced pressure.
The holding body can be rotatable or non-rotatable depending on a containing manner (the number of containing positions) of the friction material segments into the holding body. When the friction material segments are contained at one position or few positions, the holding body is preferably rotatable to contain then circumferentially. In this case, the holding body rotates, after having contained the friction material segment into respective supplying position, to position it at the supplying position. Thus, the preceding friction material segment(s) having been contained is positioned at the predetermined position circumferentially. To the contrary, when the plural friction material segments are contained whole around the holding body, the holding body needs not be rotated.
The first urging member containing the friction material segment(s) on one surface thereof can urge the friction material segment(s) toward the one surface vertical thereto, that is. vertical to a surface of the friction material segment. It also can urge the friction material segment(s) radially inwardly along the one surface, that is, in parallel to the surface of the friction material segment. The urging manner of the friction material segment(s) is associated with the location, orientation, number of the one surface and the segment holding portion.
The first urging member can contain one friction material segment, or two or more friction material segments with one operation thereof simultaneously. Configuration of the first urging member can be determined depending on the number of the friction material segments to be contained simultaneously. For example, containing one friction material segment by one operation one rod-shaped urging member each corresponding to each friction material segment can be used. On the hand, for containing all of the friction material segments required (eight to sixty) at once a ring-shaped or circular-shaped urging member can be used.
In containing the friction material segments at one or few position(s) into the holding body by one or few rod-shaped first urging member(s), the first urging member(s) and the holding body cooperate with each other so that, after containing of at least one friction material segment, the succeeding friction material segment is contained sequentially in the circumferential direction. For such cooperation, the holding body can rotate by the predetermined angle in every containing of the friction material segment (intermittently).
When the first urging member forms a part of the segment preparing member, a rest of it is formed by the holding body. For example, the segment preparing member can be constructed by an entry portion of the concaved portion as the segment holding portion, and a tip end portion of the rod-shaped urging member to be inserted into the above concaved portion. In this case, the first urging member and the holding body need to have punching blade to punch the band-shaped friction material to form the friction material segment. The first urging member and the holding body sufficiently have one punching blade respectively in punching band-shaped friction material at one portion, but they should have two punching blades respectively in punching it at two portions. Constructing the part of the segment preparing member by the first urging member reduces the number of parts necessary for preparing and containing the friction material segments.
For making the holding body having contained the friction material segments and the core plate supported on the supporting member come near, holding body and/or the core plate need to be moved so that the one surface and the adhering surface come near to each other. For this purpose, only the holding body or only the core plate can be moved, or both of the holding body and the core plate can be moved. When the holding body moves relative to the fixed core plate, it can revolve about a revolving axis, or can move in a direction parallel or vertical to the one surface thereof.
The supporting member supporting the core plate preferably has at least a mounting surface for the core plate and an attaching/detaching mechanism for the core plate. Preferably, it is rotatable to coat an adhesive agent on an adhering surface of the core plate.
The second urging member for adhering the friction material segments held in the holding body to the core plate by urge is preferably shifted relative to the holding body. It can shift in the opposite direction to the first urging member on the same axis or different (parallel) axes, or it can shift in the vertical direction to the first urging member. The second urging member capable of abutting at a part thereof to the friction material segment, retracts when the friction material segment is contained in the holding body but advances when it is adhered to the core plate. For urging the second urging member, mechanical means such as a rod-shaped urging member or a hydraulic means such as an air cylinder or an oil cylinder can be used. The mechanical means usually pushes out the friction material segments, but the hydraulic means can push out or draw-out them.
In addition, the second urging member can adhere the friction material segments one by one, but preferably adhere all of the contained friction material segments simultaneously to shorten the time period necessary for adhering the friction material segments to the core plate.
The embodying modes described in the each of the holding body, the first urging member, the supporting member, the second supporting member and the segment preparing member capable of combining selectively should be noted.